You have very good signal strength. The NRB logs show a dissassociate with a reason code of 63 (reserved), that I don't recognize. Reason code 6 is Class 2 frame received from non-authenticated STA (ok).
What channel are you using? I wonder if there has been some strong temporary interference.
Have you set the Distance on both sides?
Can you try running the Channel Optimization and see if it selects a different channel this time?
i using 108 channel with smartselect option. i set 2 Km distances. According to log,what do you think problem ? do you thinh it is interferenced? Would you recommend that i use the "Wireless spectrum analyzer " program? İf yes,Which antenna side do i use? But you dont think interfecerenced ? i am so confused